/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

import UIKit

final class LabelCell: UICollectionViewCell {

    fileprivate static let insets = UIEdgeInsets(top: 8, left: 15, bottom: 8, right: 15)
    fileprivate static let font = UIFont.systemFont(ofSize: 40)

    static var singleLineHeight: CGFloat {
        return font.lineHeight + insets.top + insets.bottom
    }

    static func textHeight(_ text: String, width: CGFloat) -> CGFloat {
        let constrainedSize = CGSize(width: width - insets.left - insets.right, height: CGFloat.greatestFiniteMagnitude)
        let attributes = [ NSAttributedString.Key.font: font ]
        let options: NSStringDrawingOptions = [.usesFontLeading, .usesLineFragmentOrigin]
        let bounds = (text as NSString).boundingRect(with: constrainedSize, options: options, attributes: attributes, context: nil)
        return ceil(bounds.height) + insets.top + insets.bottom
    }

    lazy var label: UILabel = {
        let label = UILabel()
        label.backgroundColor = .clear
        label.numberOfLines = 1
        label.font = LabelCell.font
        self.contentView.addSubview(label)
        return label
    }()

    lazy var separator: CALayer = {
        let layer = CALayer()
        layer.backgroundColor = UIColor(red: 200 / 255.0, green: 199 / 255.0, blue: 204 / 255.0, alpha: 1).cgColor
        self.contentView.layer.addSublayer(layer)
        return layer
    }()

    override func layoutSubviews() {
        super.layoutSubviews()
        let bounds = contentView.bounds
        label.frame = bounds.inset(by: LabelCell.insets)
        let height: CGFloat = 0.5
        let left = LabelCell.insets.left
        separator.frame = CGRect(x: left, y: bounds.height - height, width: bounds.width - left, height: height)
    }

    override var canBecomeFocused: Bool {
        return false
    }

}
